Abstract: A direct resistance heating simulation method is provided. In this method, a welding region and its peripheral region of steel sheets to be welded by a pair of electrodes are divided into a plurality of elements. A coupled analysis is performed such that a temperature, a metal structure, stress and strain at each element are determine in a mutually associated manner based on Joule loss obtained through a current analysis and a magnetic field analysis for each element. The coupled analysis is repeated to predict an effect of one or more parameters, including at least one of a frequency, a magnitude and an application time of electric current to be applied to the electrodes, a cooling time, a pressure applied from the electrodes to the steel sheets and a shape of the electrodes, on welding quality after a post-heating by direct resistance heating and to improve weld strength.

Abstract: A cigarette rod wherein a flexible tubular insert is surrounded by smokable material which, in turn, is surrounded by a wrapper of cigarette paper is formed by advancing the insert from a source at a variable speed toward one or more stations where the running insert is confined between two layers of smokable material. A combined monitoring and regulating system is provided to monitor the extent of sag of the insert between the outlet of the source and the confining station(s), to generate signals denoting the extent of sag, and to regulate the speed of a motor for the insert at the outlet of the source in response to such signals. The purpose of the combined signal generating and regulating system is to maintain the extent of sag of the insert between an upper threshold value and a lower threshold value.